Jacques Seligmann & Co., Inc., maintained extensive files to track important clients and collectors in the art world. The files within this series reflect the wide scope of contacts and collector references maintained by the firm throughout its operating years. The series is further subdivided into several subseries based on type of reference file.

The first and largest subseries, titled Collectors (Series 2.1), traces artwork owned and sold by private American and European collectors and galleries, with descriptions and sale prices noted, present location of works of art, when known, along with photographs of art pieces and occasional physical descriptions and exhibition text. The Museum Files (Series 2.2) reflects a similar function and arrangement as the Collectors (Series 2.1) files but mainly concerns artwork held, donated to, or purchased by major American and European museums.

Jacques Seligmann & Co., Inc., acted as agents in the sales of several large and important art collections. Files in the Duc d'Arenberg Collection (Series 2.3) document the involvement in the late 1940s of Jacques Seligmann & Co. in the sale of objects from the d'Arenberg family's manuscript collection and the firm's activities in arranging for treatment and eventual sale of a select group of paintings that included Jan Vermeer's Antoine Watteau's and Rembrandt van Rijn's The firm also conducted sales for the executors of the Estate of Clarence H. Mackay (Series 2.4) in 1939. As a wealthy American collector of Renaissance art and antiquities, Mackay had amassed a large and impressive collection, but many of the items lacked complete documentation. Seligmann & Co. undertook the task of describing, photographing, and documenting the collection in preparation for its dispersal through gallery sales and auction. The Mortimer L. Schiff Collection (Series 2.5) documents the 1937-1938 sale at Christie's of London auction house that was arranged by Jacques Seligmann & Co., Inc., to handle the disposition of the vast art collection of American banker Mortimer L. Schiff. The collection consisted of important oil paintings, watercolors, and drawings by Flemish, French, and German masters, English drawings and watercolors, Beauvais tapestries, Gothic and Renaissance sculpture and bronze, Chinese porcelains, Gothic and Renaissance arms and armor, and decorative arts. The Prince of Liechtenstein Collection (Series 2.6) documents the 1953 purchase by Jacques Seligmann & Co., Inc., of seven Italian marble sculptures from the Prince of Liechtenstein. The sculptures were subsequently sold to the Samuel H. Kress Foundation in 1954.

Jacques Seligmann & Co., Inc., maintained a variety of records to track the location of important pieces of art as well as background material and addresses of collectors of note. Old Collectors of Interest (Series 2.7) consists of documents that were originally contained in two looseleaf volumes, generally compiled circa 1938-1952, but there are infrequent sales data from earlier dates. The information includes names and addresses of collectors, details of artwork or collections owned by the collectors, along with references to listings or reproduction in art catalogs. Most of this information appears to come directly from the catalogs, but some items record the observations and impressions of Germain Seligman after personally viewing the collection or object. Materials in the Blue Book of Collectors (Series 2.8) were originally contained within a blue-covered looseleaf notebook. Entries list collectors along with their address and occasional details of the artwork they owned. The entries date largely from 1956. Collections Books (Series 2.9) includes four looseleaf notebooks dating from the late 1920s to the mid-1950s that maintained information related to the holdings of art collectors, individual works of art, and negotiations related to the sales or purchases of works of art. The first volume serves as an index to the other three volumes and is arranged by artist and collector or collection. The other three volumes contain memoranda for the record by Germain Seligman, letters and telegrams, lists of works viewed by Seligman along with his opinions about them, and his accounts of conversations held with owners regarding their willingness to sell items. Prospective Clients (Series 2.10) consists of records from five looseleaf binder notebooks. The books contain entries made between the mid-1930s and the mid-1950s by Germain Seligman concerning people he viewed as potential clients, along with notations as to why he viewed them that way. File cards were subsequently made from these files and added to Jacques Seligmann & Co., Inc., mailing lists. Reserve Notebooks (Series 2.11) consists of records from four spiral notebooks that list client, artwork under consideration, and related material. Entries from the mid-1960s to early 1970s document clients who expressed an interest in a particular work or type of art as well as actual customer requests to reserve a particular work. People of Interest (Series 2.12) consists of additional files maintained on people viewed as potential clients that were largely compiled by Germain Seligman and other staff members during their trips to visit museums, collections, or individual owners or buyers of art. The information centers on American clients, but occasional European customers are also included. The records largely date from 1930 to 1950, with the records regarding Paris and the French provinces dating from 1963 to 1974. European Collectors (Series 2.13) has information similar to that in People of Interest (Series 2.12) but for European and South American regions and in a card file format. The records cover the period from the mid-1930s to the early 1970s.

The Collectors Files series is arranged into the following subseries. More detailed descriptions for each of the subseries follow with a corresponding box and folder inventory.

The bulk of this series has been scanned. Details of exceptions are provided in the arrangement notes for each subseries.